Z. Naturforsch. 2013,
68b, 587 – 597
doi:10.5560/ZNB.2013-3033
Oxidation Reactions Catalyzed by Polyoxomolybdate Salts
Bo
Zhang1,
Su
Li1,
Alexander
Pöthig1,
Mirza
Cokoja1,
Shu-Liang
Zang2,3,
Wolfgang A.
Herrmann1, and
Fritz E.
Kühn1
1 Chair of Inorganic Chemistry/Molecular Catalysis, Catalysis Research Center, Technische Universität München, Ernst-Otto-Fischer-Straße 1, D-85747 Garching bei München, Germany
2 School of Chemical and Materials Science, Liaoning Shihua University, Dandong Road, No.1, 113001 Fushun, P. R. China
3 Institute of Rare and Scattered Elements Chemistry, Liaoning University, Chongshan Middle Road No. 66, 110036 Shenyang, P. R. China
Received January 30, 2013 / published online Juli 2, 2013
Dedicated to Professor Heinrich Nöth on the occasion of his 85th birthday
Ionic compounds containing the polyoxomolybdate anion [Mo6O19]2− and [(n-C4H9)4P]+ (tetrabutylphosphonium), [(n-C4H9)3P(n-C14H29)]+ (tributyl (tetradecyl)phosphonium), [Bmim]+ (1-butyl-3-methylimidazolium) and [Dbmim]+ (1,2-dimethyl-3-butylimidazolium) cations were prepared and characterized, including the determination of three of the solid state structures by single-crystal X-ray diffraction. These compounds were applied as catalysts for the epoxidation of olefins with urea hydrogen peroxide (UHP) as oxidant in the ionic liquid [Bmim]PF6. Additionally, the
oxidation of sulfides to sulfoxides with hydrogen peroxide (H2O2) in several solvents was investigated. The polyoxomolybdate catalysts showed a good performance for epoxidation of olefins as well as for oxidation of sulfides. Furthermore, the catalysts can be recycled several times in oxidation reactions. We present this methodology for the oxidation reaction in a simple, economically, technically, and environmentally benign manner.
Key words: Catalysis, Ionic Liquids, Molybdenum, Oxidation, Polyoxomolybdate, Epoxides, Sulfoxides